Chucks are known from the prior art, for example from DE 140 638 A1 [U.S. Pat. No. 6,568,888], that by means of collet chucks are used to clamp workpieces having, for example, a collet. To actuate such chucks, actuators, also referred to as release units, are used that axially displace a rod associated with the chuck, and to clamp the workpiece the rod is pulled in the direction away from the collet chuck and, with application of the necessary clamping force, is held in this position by the actuator, the correct positioning of the rod being assisted by spring-washer assemblies or helical spring washers. The actuator moves the rod in the opposite direction to discontinue the clamping. Although such chucks with associated actuators and the method required for their operation have proven to be successful in practice, the known prior art has limitations when the balance quality must be continually improved as rotation speeds of the spindle increases, and in particular the spring-washer assemblies or helical spring washers have an adverse effect since they bear continuously on the rod.